Method of converting feedstocks from renewable sources to good-quality diesel fuel bases using a zeolite type catalyst

Abstract

A method of treating feedstocks from renewable sources in order to produce diesel fuel bases of excellent quality. The feedstocks used can be, for example, raw vegetable oils or such oils that have been previously subjected to a prerefining stage, animal fats, or mixtures of such feedstocks. The method includes fixed bed catalytic hydrotreatment, followed by fixed bed hydroisomerization with a catalyst based on monodimensional 10 MR zeolite and at least one metal from group VIII and/or VIB.

1. A method of treating a feedstock from a renewable vegetable or animal source, comprising the following stages:
 a) subjecting the feedstock to hydrotreatment in the presence of a fixed-bed catalyst, said catalyst comprising a hydro-dehydrogenizing function and an amorphous support, at a temperature ranging between 200° C. and 450° C., at a pressure ranging between 1 MPa and 10 MPa, at an hourly space velocity ranging between 0.1  −1  and 10 h −1  and in the presence of a total amount of hydrogen mixed with the feedstock such that the hydrogen/feedstock ratio ranges between 150 and 750 Nm 3  hydrogen/m 3  feedstock to produce an effluent, 
 b) separation, from the effluent from stage a), of the hydrogen, other gases and at least one hydrocarbon-containing base, 
 c) hydroisomerization of at least part of said hydrocarbon-containing base from stage b) in the presence of a fixed-bed hydroisomerization selective catalyst, said catalyst comprising at least one group VIII metal and/or at least one VIB group metal and at least one monodimensional 10 MR zeolite molecular sieve, said stage c) being carried out at a temperature ranging between 150° C. and 500° C., at a pressure ranging between 1 MPa and 10 MPa, at an hourly space velocity ranging between 0.1 h −1  and 10 h −1  and in the presence of a total amount of hydrogen mixed with the feedstock such that the hydrogen/feedstock ratio ranges between 70 and 1000 Nm 3 /m 3  feedstock to produce an effluent, 
 d) separation, from the effluent from stage c), of the hydrogen, other gases and at least one diesel fuel base. 
 
     
     
       2. A method as claimed in  claim 1 , wherein stage a) operates in the presence of a total amount of hydrogen mixed with the feedstock such that the hydrogen/feedstock ratio ranges between 150 and 700 Nm 3  hydrogen/m 3  feedstock. 
     
     
       3. A method as claimed in  claim 2 , wherein stage a) operates in the presence of a total amount of hydrogen mixed with the feedstock such that the hydrogen/feedstock ratio ranges between 150 and 650 Nm 3  hydrogen/m 3  feedstock. 
     
     
       4. A method as claimed in  claim 2 , wherein stage a) operates in the presence of a total amount of hydrogen mixed with the feedstock such that the hydrogen/feedstock ratio ranges between 150 and 600 Nm 3  hydrogen/m 3  feedstock. 
     
     
       5. A method as claimed in  claim 1 , wherein the total proportion of oxides of group VIB and VIII metals in the catalyst used in stage a) ranges between 5 and 40% by weight in relation to the total mass of catalyst. 
     
     
       6. A method as claimed in  claim 1 , wherein said monodimensional 10 MR zeolite molecular sieve of said fixed bed hydroisomerization catalyst is selected from among the zeolite molecular sieves of TON structural type, including NU-10, EUO, selected from among EU-1 and ZSM-50, taken alone or in admixture, or zeolite molecular sieves ZSM-48, ZBM-30, IZM-1, COK-7, EU-2 and EU-11, alone or in admixture. 
     
     
       7. A method as claimed in  claim 6 , wherein said monodimensional 10 MR zeolite molecular sieve is selected from among the zeolite molecular sieves ZSM-48, ZBM-30, IZM-1 and COK-7, alone or in admixture. 
     
     
       8. A method as claimed in  claim 7 , wherein said monodimensional 10 MR zeolite molecular sieve is selected from among the zeolite molecular sieves ZSM-48 and ZBM-30, alone or in admixture. 
     
     
       9. A method as claimed in  claim 8 , wherein said monodimensional 10 MR zeolite molecular sieve is ZBM-30. 
     
     
       10. A method as claimed in  claim 9 , wherein said monodimensional 10 MR zeolite molecular sieve is ZBM-30 synthesized with the triethylene tetramine organic structurant. 
     
     
       11. A method as claimed in  claim 1 , wherein said hydroisomerization catalyst comprises either at least one noble metal of group VIII or at least one metal of group VIB, in combination with at least one non-noble metal of group VIII. 
     
     
       12. A method as claimed in  claim 1 , wherein the fixed bed hydroisomerization catalyst in stage c) comprises a noble metal content ranging between 0.01 and 5% by weight in relation to the finished catalyst. 
     
     
       13. A method as claimed in  claim 1 , comprising the group VIB metal the fixed bed hydroisomerization catalyst in stage c) in a content which ranges, in oxide equivalent, between 5and 40% by weight in relation to the finished catalyst, and the group VIII metal content of said catalyst ranges, in oxide equivalent, between 0.5 and 10% by weight in relation to the finished catalyst. 
     
     
       14. A method as claimed in  claim 1 , wherein the feedstock comprises at least one vegetable oil or animal fat, essentially containing triglycerides and fatty acids or esters, with hydrocarbon fatty chains having a number of carbon atoms ranging between 6 and 25. 
     
     
       15. A method according to  claim 1 , wherein said feedstock comprises at least one of palm, palm-nut, copra, castor and cotton oil, peanut, linseed, crambe and jatropha oil, an oil resulting from sunflower or rapeseed through genetic modification or hybridization, algae oil, waste kitchen oil and animal oil. 
     
     
       16. A method comprising providing an effluent from a hydrotreatment of a renewable animal or vegetable source and subjecting the effluent to a hydroisomerization stage with at least one hydroisomerization catalyst comprising at least one group VIII and/or group VI metal and at least one monodimensional 10 MR zeolite molecular sieve, selected from among the zeolite molecular sieves of TON structural type, including NU-10, EUO, selected from among EU-1 and ZSM-50, taken alone or in admixture, or zeolite molecular sieve ZSM-48, ZBM-30, IZM-1, COK-7, EU-2 and EU-11, alone or in admixture. 
     
     
       17. A method according to  claim 16 , further comprising separating from the hydrotreatment effluent, hydrogen, other gases and at least one hydrocarbon-containing base, said separating being conducted prior to the hydroisomerization stage. 
     
     
       18. A method according to  claim 17 , further comprising separating resultant effluent to recover at least one diesel fuel base. 
     
     
       19. A method according to  claim 16 , wherein said feedstock comprises at least one of palm, palm-nut, copra, castor and cotton oil, peanut, linseed, crambe and jatropha oil, an oil resulting from sunflower or rapeseed through genetic modification or hybridization, algae oil, waste kitchen oil and animal oil. 
     
     
       20. A method according to  claim 19 , wherein said 10 MR zeolite molecular sieve is ZBM-30.